Volvo VNL Operator's Manual page 198

Heater Shut-Downs
•
If the heater does not start within
two 60 second start attempts, a "no
start" shut-down occurs.
•
If a flameout occurs after the heater
has started, the heater will attempt
to restart. If repeated flameouts oc-
cur within 10 minutes, the heater
will not restart.
•
Overheat shut-down will occur if
there is a restriction of the heating
air flow (that is: blocked inlet or
outlet). The automatic overheat
switch will reset once the heater has
cooled down.
•
The blower motor is checked on
start-up and every 4 minutes. Shut-
down will occur if the blower does
not start or maintain proper speed.
If any of these events should occur, the unit
should be checked out by a qualified heater
technician or contact the manufacturer.
Heating and Air Conditioning 193